Solid-state Polymerization of Diacetylene Microcrystals

Abstract Microcrystals of two different types of diacetylene monomers, i.e. 4BCMU known for giving a soluble polydiacetylene and 14-8 ADA known as an amphiphilic diacetylene, were prepared and in their solid-state polymerization behaviors were investigated. The polymerization of 4BCMU proceeded quantitatively in the perfect crystalline lattice to give blue-colored polymer crystals. Averaged molecular weight of poly-4BCMU was found to be. proportional to microcrystal size, implying that the solid-state polymerization proceeds from one end to the other end of microcrystals. 14-8 ADA microcrystals gave very stable water dispersion even after polymerization, so that the detailed analysis of polymerization behaviors was possible. Size-dependent spectral change and final conversion found for 14-8 ADA were discussed in terms of strain and thermal motion of the crystal lattice.